What is radioactive waste and where does it come from?

There are many definitions of the term ‘radioactive waste’, such as the one defined in Article 2 of Spanish Law 25/1964 on Nuclear Energy: ‘Radioactive waste is any waste material or product for which no use is envisaged, which contains or is contaminated with radionuclides in concentrations or activity levels higher than those established by the Ministry for Ecological Transition and Demographic Challenge, following a report by the Nuclear Safety Council’. However, they all coincide in the words ‘waste material’ and the fact that it contains radionuclides in concentrations exceeding the permitted values.

In general, human activities involving radioactive substances for various purposes, such as mining or medical applications, electricity generation, industrial applications or laboratory use, which produce ionising radiation, some of which contain isotopes in quantities above the established limits, also generate waste.

This waste does not have the same characteristics as conventional waste because it can give off heat and emit radioactivity that decays over time until it is no longer radioactive, so it must be stored in special, secure locations.

The danger posed by this waste is relative, depending heavily on the nature and concentration of the radioisotopes it contains. Therefore, its management consists precisely of treating it in such a way as to ensure that there is no risk to either people or the environment.

Radioactive waste comes mainly from the normal operation and decommissioning of nuclear reactors, but not exclusively, as it is also generated in radioactive facilities for industrial, medical (nuclear medicine), agricultural, research, mining and other purposes.